Frye, Richard N.
Henry Holt, 1953
Buku Teks SO
Frye, Richard N.
George Allen & Unwin, 1960
Buku Teks SO
Jacobs, Norman
Frederick A. Praeger, 1967
Buku Teks
Sachs, Ignacy
Cambridge University Press , 1987
Buku Teks
Tinbergen, Jan, 1903-
McGraw-Hill, 1967
Buku Teks